This invention relates to a method of exchanging bobbins in a flyer frame and an apparatus therefor.
Recently, many attempts have been made to adopt large package bobbins and high speed rotation of the flyer frame in order to contribute to the efficiency of the spinning industry. Consequently, an efficient doffing operation has become a very important problem, the solution to which is essential to the success of the adoption of the large package bobbin and high speed rotation of the flyer frame. Manual handling of large packaged bobbins means a heavy operation to workers and a prolonged work time thus considerably reducing operational efficiency of the flyer frame. Thus there is a strong demand for automation of the doffing operation and hence various devices have been proposed for automatically discharging full yarn or roving packages and automatically supplying empty bobbins.
In some of these prior-art devices, one end of the machine base is provided with a unit for automatically discharging full yarn packages and the other end is provided with a unit for automatically supplying empty bobbins. Full yarn packages delivered from the spinning machine are transferred to conveyor means interposed between said units and are discharged automatically in the course of one cycle of operation of the conveyor means, to which empty bobbins are replenished automatically. In others, an automatic full yarn package discharge unit and an empty bobbin supply unit are provided at one end of the machine base. Conveyor means are operated in the normal direction for automatically discharging full yarn packages and in the reverse direction for automatically replenishing empty bobbins.
However, in the former device, the place of discharging full yarn packages is separated from the place of replenishing empty bobbins, thus greatly increasing operational inconvenience. In the latter device, a complicated operation is involved in switching between normal and reverse operations of the conveyor means and in alternately connecting the full yarn package discharge unit and the empty bobbin supply unit to the conveyor means. In addition, in these prior-art devices, since the discharged full yarn packages are stacked on a conveyor car for transport to the subsequent step, the yarn tends to be damaged. The full yarn bobbins must be taken out of the conveyor car manually which considerably interferes with the automation of the operation in the subsequent step.
In order to overcome such deficiency, it has also been proposed to provide an overhead girder from which is hung a conveyor magazine which in turn carries full yarn packages discharged from the conveyor means by an automatic discharge unit for transport to the subsequent spinning process. However, the spinning machine is usually operated on a 24-hour basis to improve the overall operational efficiency of the spinning plant. Thus it is necessary to store fresh full yarn bobbins at all times on a large number of conveyor rails, in addition to the usual conveying route from the conveyor means to the spinning machine, thus considerably increasing investment costs.
In addition, the aforementioned prior-art automatic empty bobbin supply device has a drawback in that a large space is required for storing a large number of empty bobbins besides the empty bobbin supply device adapted for separately supplying empty bobbins to bobbin holders on the conveyor means, said empty bobbins being large-sized due to adoption of large package bobbins.